Water Tanks, page-46

Have 2 tanks in series, a poly above ground and that leads into a concrete underground tank if I open the valve,both have their own downpipes. there's 2 water areas in a tank, the aerobic zone and a lower anaerobic zone, may want to check the smell is not related to draining and perhaps the tank is healthy. you can always take some water to a test facility. for under a few hundred bucks you get professional testing of heavy metals and 7 common pesticides, they'll also throw others in if you need them like sulfur into your test.